Cementitious composites

Abstract

A method of improving the stress strain characteristics, the ductility, the energy absorbing characteristics, the fractal roughness and the material roughness of a cementitious mix includes adding at least 1%, by weight of the total weight of the cementitious mix of poly(vinyl butyrate) in addition to a reinforcing agent, preferably poly(vinyl alcohol). In a preferred embodiment, the amount of poly(vinyl butyrate) is about 40% to about 50%, by weight. This provides the optimum levels of performance of the characteristics listed above.

1 ) A cementitious mix comprising:
 a) a cement; and   b) an aggregate which includes at least 1% by weight of the total weight of the cementitious mix, of poly(vinyl butyral).   
   
   
       2 ) The cementitious mix of  claim 1  further comprising water to form a cementitious matrix. 
   
   
       3 ) The cementitiuos matrix of  claim 2  further comprising a reinforcing material. 
   
   
       4 ) The cementitious matrix of  claim 3  wherein the amount of poly(vinyl butyral) is at least 1% to about 50%, by weight of the total weight of the cementitious mix. 
   
   
       5 ) The cementitious matrix of  claim 4  wherein the amount of poly(vinyl butyral) is from about 10% to about 55%, by weight of the total weight of the cement cementitious matrix. 
   
   
       6 ) The cementitious matrix of  claim 3  wherein the reinforcing material is selected from the group consisting of plastics, resins, ceramics, glass fibers, aramid fibers, carbon fibers and poly(vinyl alcohol). 
   
   
       7 ) The cementitious matrix of  claim 6  wherein the reinforcing material is poly(vinyl alcohol). 
   
   
       8 ) The cementitious matrix of  claim 7  wherein the poly(vinyl alcohol) is present in an amount of from about 0.1% to about 3%, by weight of the total weight of the cementitious matrix. 
   
   
       9 ) The cementitious matrix of  claim 8  wherein the poly(vinyl alcohol) is present in an amount of about 0.9%, by weight of the total weight of the cementitious matrix. 
   
   
       10 ) The cementitious matrix of  claim 2  further comprising cerium oxide in an amount of about 0.01% to about 1%, by weight of the total weight of the cementitious matrix. 
   
   
       11 ) The cementitious matrix of  claim 2  further comprising metakaolin in an amount up to about 5%, by weight of the weight of the cement in the cementitious matrix. 
   
   
       12 ) The cementitious mix of  claim 1  further comprising pozzolan in an amount of up to 10%, by weight of the weight of the cement in the cementitious mix. 
   
   
       13 ) The cementitious matrix of  claim 2  further comprising silica fume in an amount up to about 10% by weight of the weight of the cement in the cementitious matrix. 
   
   
       14 ) The cementitious matrix of  claim 2  further comprising a superplasticizer in an amount up to about 3%, by weight of the total weight of the cementitious matrix. 
   
   
       15 ) The cementitious matrix of  claim 14  wherein the superplasticizer is polycarboxylate. 
   
   
       16 ) The cementitious matrix of  claim 2  further comprising an aqueous latex in an amount of from about 10% to about 50%, by weight of the total weight of the cementitious matrix. 
   
   
       17 ) The cementitious matrix of  claim 16  wherein the latex compound is selected from the group consisting of a styrene butadiene latex, a PVAC, PVOH, EVAC or EVOH latex and an aqueous latex. 
   
   
       18 ) A method of increasing tensile strength of a cementitious mix comprising adding poly(vinyl butyrate) to the cementitious matrix in an amount of at least 1%, by weight of the total weight of the cementitious mix. 
   
   
       19 ) The method of  claim 18  wherein the amount of poly(vinyl butyrate) is present in an amount of at least 1% to about 50%, by weight of the total weight of the cementitious matrix. 
   
   
       20 ) A cementitious matrix comprising:
 a) a cement;   b) an aggregate material;   c) a fiber reinforcing material that binds to the aggregate material; and   d) water.   
   
   
       21 ) The cementitious matrix of  claim 20  wherein the aggregate material is poly(vinyl butyral) in an amount of at least 1% to about 50%, by weight of the total weight of the cementitious matrix, the fiber reinforcing material is poly(vinyl alcohol) in an amount of about 0.1 to about 3%, by weight of the total weight of the cementitious matrix and the water is present in an amount of about 25% or greater, by weight, based on the weight of the cement. 
   
   
       22 ) A cementitious mix comprising:
 a) a cement; and   b) an aggregate comprising a material including surface hydroxyl groups and ether groups, wherein the material is present in an amount of at least 1% by weight of the weight of the cementitious mix.